Patent · US Expired

Method and apparatus for bidirectional demodulation of digitally modulated signals

US5909465A · kind A · utility

60Cited by
13References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 5, 1996
Grant dateJun 1, 1999
Priority date
Expiry dateDec 5, 2016

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L2025/0356
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A system and method for bidirectionally demodulating data symbols transmitted through a communication channel. The method includes sequentially receiving and storing a first plurality of known data symbols, a second plurality of unknown data symbols, and a third plurality of known data symbols. Thereafter, a first block of the unknown data symbols received nearer the first plurality of known data symbols is forward-demodulated. Likewise, a second block of the unknown data symbols received nearer the third plurality of known data symbols is backward-demodulated. The forward- and backward-demodulation of the unknown data symbols determines quality values (figure-of-merits based on at least one of signal power, noise power and a combination of signal power plus noise power) indicative of demodulation qualities of the unknown data symbols that are compared to produce a best direction indication. Upon determining the best direction indication, either the forward- or backward-demodulation steps are repeated for subsequent blocks of unknown data symbols.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.